Master PR: https://github.com/droolsjbpm/jbpm-designer/pull/241
6.4.x commit https://github.com/droolsjbpm/jbpm-designer/commit/623e8925b55c864b4644220fc6fb3d1fb349d61b
6.3.x PR https://github.com/droolsjbpm/jbpm-designer/pull/247
6.3.x commit https://github.com/droolsjbpm/jbpm-designer/commit/16c5696847a452cd6b448248e114a9791335c878
Ok, I verified that this issue has been fixed with 6.2.3 patch.